This invention relates to tufting machines, and more particularly to a tufting machine having means for selecting one, two, both or neither needle to stitch a loop in accordance with a pattern, and which can effect a substantially smaller gauge between adjacent rows of stitches made by selectable or controlled needles then heretofore.
Controlled needle tufting machines are known in the art for selectively engaging and dispensing, in skip-stitch fashion, various of the needles in accordance with a program during each reciprocatory cycle of the needle driving push rods. Basically these machines render selective needles or groups of needles inoperative while the remainder of the needles are operative to pierce and penetrate the backing fabric upon each stroke of the push rods. Examples of these machines are illustrated in U.S. Pat. Nos. 3,115,856; 3,259,088; 3,881,432 and 3,986,465, and in Slattery copending application Ser. No. 07/140,480, filed on Jan. 4, 1988 and assigned to the same assignee as the present invention. Such machines have been very successful, especially for producing bed spreads, and in the case of individually controlled needle tufting machines have been widely accepted for overtufting a design into a pretufted fabric, as described in U.S. Pat. No. 4,693,190.
In these machines each needle cooperates with its own respective loop seizing hook and each hook cooperates with but one needle. However, although it is believed that sometime ago attempts were made to provide a tufting machine wherein one of two needles could be selected to sew with a single loop seizing member on a particular drive stroke or machine cycle, no such machine is known or believed to have been developed or constructed.
Additionally, the major limitation of individually controlled needle tufting machines has been the gauge or spacing between adjacent needles, i.e., the spacing between adjacent needles and thus between adjacent rows of stitches is larger than that which is desirable for a commercially aesthetic carpet. This is a direct result of the size of the needle bar and needle holders required for supporting the needles. For example although a 5/32nd gauge individual controlled needle (hereinafter "I.C.N.") machine has been constructed, the usual gauge is 3/16th and larger. Such machines, as aforesaid, have been widely accepted for overtufting a design into a pretufted carpet fabric wherein the base fabric has a finer gauge and the larger gauge I.C.N. is utilized for forming the design or pattern. Even for such overtufting operations greater design flexibility can be obtained if the gauge were smaller, such as 3/32nd gauge.
Furthermore, as noted in Bardsley copending application Ser. No. 07/123,258, filed Nov. 20, 1987 and assigned to the same assignee as the present application, if a controlled needle machine were developed wherein at least one of two needles could be selected to form a stitch in a given row of stitching, the needles could be threaded with different yarns, such as yarns of different color so that on any particular stitch the color could be selected. Although such a machine is disclosed in the aforesaid copending application of Bardsley, that machine does not have the capability of selecting both needles in a given row of stitching. Again, physical limitations in the machine there proposed preclude the versatility of selecting one or the other of the needles, neither needle and both needles. If both needles could be selected while still maintaining the capability of selecting one or the other of the needles, or neither needle, each needle could be threaded with a different color yarn to provide a multitude of patterning effects and color variations not heretofore possible in tufting machines to produce carpet fabric which heretofore could only be produced by the more costly weaving process on a loom. A controlled needle tufting machine having dual needles which may be individually controlled selectively to place one color yarn, or another color yarn, or neither yarn, or both yarns would provide a carpet designer with the freedom to perform creative and aesthetic designs having mass appeal at affordable cost. Moreover, the versatility of such a machine would be substantially increased if the gauge between adjacent needles could be varied to produce conventional I.C.N. products having half the gauge of the gauge between adjacent needles in a particular row thereof.